The word glassworkers is playable in Words With Friends™, no blanks required. Because it is longer than 7 letters, you would have to play off an existing word or do it in several moves.
Words With Friends™ Letter Score: 22
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (36 words)
arkoses, gaolers, gasless, gassers, gaswork, gawkers, glasses, glosser, glosses, glowers, grasses, grosser, grosses, growers, growler, largess, lassoer, lassoes, leasows, legwork, lessors, oarless, ragwork, regloss, reglows, regrows, resoaks, rewalks, reworks, soakers, soarers, sorrels, walkers, warless, workers, wrasses